Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 4.844
Filtrar
1.
Bioresour Technol ; 301: 122727, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31983577

RESUMO

Interest in microalgae-derived products is growing, mostly due to their unique characteristics and range of industrial applications. To obtain different products, one must employ specific pretreatments that retain the properties of the biologically active compounds extracted from microalgae biomass; thus, new extraction techniques require frequent upgrades. Due to increased interest in economically viable and ecologically friendly processes, new extraction methods that can be incorporated into microalgae biorefinery systems have become the main focus of research. Therefore, this review aims to address the potential applications, future prospects, and economic scenario of the new physicochemical treatments used in the extraction of bioactive microalgae compounds.


Assuntos
Microalgas , Biocombustíveis , Biomassa
2.
Bioresour Technol ; 300: 122677, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31901777

RESUMO

Upflow anaerobic sludge blanket (UASB) reactors are widely used to treat domestic sewage and frequently require post-treatment. Little is known about the use of high rate algal ponds (HRAP) for post-treating UASB reactors' effluent. This study aimed to evaluate a UASB reactor followed by a HRAP in terms of sewage treatment efficiency and biogas production, during one year at demonstration-scale. The UASB reactor co-treated raw sewage and the harvested microalgal biomass from the HRAP, which was recirculated to the reactor. An identical UASB reactor, treating only raw sewage, was used as control. The results showed an overall removal of 65% COD and 61% N-NH4 in the system. Furthermore, methane yield was increased by 25% after anaerobic co-digestion with microalgae, from 156 to 211 NL CH4 kg-1 VS. An energy assessment was performed and showed a positive energy balance, with a net ratio of 2.11 to the annual average.


Assuntos
Microalgas , Esgotos , Anaerobiose , Biocombustíveis , Reatores Biológicos , Metano , Eliminação de Resíduos Líquidos
3.
Bioresour Technol ; 300: 122688, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31901780

RESUMO

The optimal operational parameters of a second generation magnetically induced membrane vibration (MMV) system were determined using the response surface methodology (RSM) combined with single-factor experiments. The membrane surfaces were characterized by scanning electron microscopy (SEM) and algae cell states by inverted microscopy. The effect of an intermittent vibration strategy on filtration performance and energy consumption was studied. The results showed that the responses could be fitted by RSM models. High membrane flux, low energy consumption, efficient fouling control and no damage to the microalgae could thus be realized. The filtration strategy tests suggested that an intermittent cycle time of 4 min with 50% vibration rate could be the best vibration strategy for harvesting the microalgae under investigation.


Assuntos
Microalgas , Filtração , Membranas Artificiais , Vibração
4.
Bioresour Technol ; 300: 122665, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31918303

RESUMO

Microalgae bio-oil production is related to the sustainable use of world energy in the future. In the present work, catalytic pyrolysis and liquefaction behavior of microalgae for bio-oil production were investigated. The results show that the rare earth compounds as catalysts contributed to significantly accelerating the pyrolysis of microalgae via reducing the activation energy of pyrolysis process. Ce(II)/HZSM-5 presented the optimal catalytic pyrolysis and liquefaction effects by helping cut the microalgae molecule chains. The maximum bio-oil yield amounted to 49.71 wt% at the catalyst concentration of 5 wt%. The chemical components of the Spirulina bio-oil were composed of carboxylic acids, ketones, olefins, amides, ethers, esters, and partially cyclic N-containing compounds. Although the combustion performances of the Spirulina bio-oil are worse than those of the diesel fuel, it is superior to the reported rice husk bio-oil, suggesting a promising potential application prospect.


Assuntos
Microalgas , Biocombustíveis , Catálise , Temperatura Alta , Óleos Vegetais , Polifenóis , Pirólise
5.
Water Res ; 171: 115441, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31927090

RESUMO

This study is an analysis of relationships between microalgae (measured as chlorophyll a) and the fecal indicator bacteria enterococci. Microalgae blooms and enterococci exceedances have been occurring in Florida's recreational waterways for years. More recently, this has become a management concern as microalgae blooms have been attributed to potentially toxic cyanobacteria, and enterococci exceedances link to human infection/illness. Since both the microalgal blooms and bacterial exceedances occur in regions that receive managed freshwater releases from Lake Okeechobee, we hypothesized that both the blooms and exceedances are related to excess nutrients from the lake. Two experimental sites, on Lake Okeechobee and the St. Lucie River (downstream of the lake), plus a control site on the Loxahatchee River (which does not receive lake flow) were evaluated. The hypothesis was evaluated through three study components: 1) analysis of available long-term data from local environmental databases, 2) a year-long monthly sampling and analysis of chlorophyll a, enterococci, nutrients, and physical-chemical data, and 3) microcosm experiments with altered water/sediment conditions. Results support the hypothesis that excess nutrients play a role in both chlorophyll a and enterococci levels. For the St. Lucie River, analyses indicate that chlorophyll a correlated significantly with total Kjeldahl nitrogen (TKN) (R2 = 0.30, p = 0.008) and the strongest model for enterococci included nitrate-nitrite, TKN, total phosphorus, orthophosphorus, and turbidity in our long-term analysis (n = 39, R2 = 0.83, p ≤ 0.001). The microcosm results indicated that chlorophyll a and enterococci only persisted for 36 h in water from all sources, and that sediments from Lake Okeechobee may have allowed for sustained levels of chlorophyll a and enterococci levels. Overall similarities were observed in chlorophyll a and enterococci relationships with nutrient concentrations regardless of a Lake Okeechobee connection, as underscored by a study of flow out of the lake and downstream areas. This suggests that both nutrient-rich lake water and untreated surface water runoff contribute to microalgae blooms and enterococci exceedances in southeast Florida.


Assuntos
Lagos , Microalgas , Proliferação de Células , Clorofila , Clorofila A , Enterococcus , Monitoramento Ambiental , Eutrofização , Florida , Nitrogênio , Fósforo
6.
Bioresour Technol ; 301: 122743, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31945684

RESUMO

The aim of this work was to investigate the potential of PEF technology for green extraction of microalgal pigments and lipids from fresh Chlorella sorokiniana suspensions. Efficiencies of PEF treatment and different solvent systems application to C.sorokiniana were compared to efficiencies of untreated biomass extraction. Differences in chlorophyll extraction of untreated and PEF treated C.sorokiniana were only seen at short extraction times. Beneficial PEF-effect was minimised for long-time extractions of larger algae quantities where yields aligned. Extraction attempts on C. sorokiniana lipids did not show increased extractability after PEF treatment, which underlined the statement of PEF representing a rather ineffective disruption method for microalgae holding rigid cell walls.


Assuntos
Chlorella , Microalgas , Biomassa , Clorofila , Eletricidade
7.
Water Res ; 171: 115445, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31954203

RESUMO

Ammonium removal by a coupling process of microalgae (Chlorella sorokiniana) with partial nitrifying granules was evaluated in batch reactors illuminated in a wide range of light intensities (0, 100, 450, and 1600 µmol photons m-2 s-1). Ammonium oxidation performance for different light exposure time showed that the granules had a light stress tolerance at 1600 µmol photons m-2 s-1 for up to 12 h, but continuous illumination induced severe inhibition on nitrifying bacteria thereafter. Ammonium removal efficiencies at the end of tests were 66%, 62%, 5%, and -10% (due to ammonification) for 0, 100, 450, and 1600 µmol photons m-2 s-1, respectively. The nitrogen mass balance shows co-occurrence of microalgal growth taking up 24% of fed ammonium and nitrifying bacteria oxidizing 38% of fed ammonium at 100 µmol photons m-2 s-1, while both nitrification and microalgal growth are inhibited at light intensity above 450 µmol photons m-2 s-1. In comparing results from this study with previous results, it was found that the ammonium removal pathway, i.e., nitrification or microalgal uptake, is regulated more strongly by daily average light intensity than by instantaneous light intensity. Empirical model equations to estimate the oxygen balance in consortium reactors categorized the effect of daily average light intensities on process performance as follows: (i) below 27 µmol photons m-2 s-1: insufficient oxygen for nitrification; (ii) 27 to 35: sufficient oxygen for nitrification via nitrite; (iii) 35 to 180: sufficient oxygen for nitrification via nitrate; (iv) above approximately 200-300: oversaturated dissolved oxygen, excess free ammonia and/or intensive light inhibitions.


Assuntos
Compostos de Amônio , Chlorella , Microalgas , Amônia , Reatores Biológicos , Nitrificação , Nitritos , Nitrogênio
8.
Bioresour Technol ; 301: 122774, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31954973

RESUMO

The thermal characteristics of Actinobacillus succinogenes (AS) from pyrolysis, torrefaction, and combustion are analyzed to evaluate the potential of this biomass as a renewable fuel. AS pyrolysis can be classified into four stages, and its main decomposition zone is at 200-500 °C. The solid yield of AS after 60 min torrefaction is over 60 wt%, and the torrefaction severity index map indicates that a high torrefaction temperature with a short duration has a more profound influence on its decomposition. The Py-GC/MS analysis of AS suggests that the volatile products from 500 °C pyrolysis are similar to microalgae-derived pyrolysis bio-oils. The combustibility index (S) of AS is 4.07 × 10-7 which is much higher than that of lignite coal (0.39 × 10-7) and bituminous coal (0.18 × 10-7), and close to those of biochar and bio-oil. The obtained results are conducive to the development of microorganisms as fuel to achieve a circular bioeconomy.


Assuntos
Actinobacillus , Microalgas , Biomassa , Temperatura Alta
9.
Bioresour Technol ; 300: 122719, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31956056

RESUMO

Microalgae are sources of nutritional products and biofuels. However, their economical processing is challenging, because of (i) the inherently low concentration of biomass in algal cultures, below 0.5%, (ii) the high-water content in the harvested biomass, above 70%; and (iii) the variable intracellular content and composition. Cell wall structure and strength vary enormously among microalgae, from naked Dunaliella cells to robust Haematococcus cysts. High-value products justify using fast and energy-intensive processes, ranging from 0.23 kWh/kg dry biomass in high-pressure homogenization, to 6 kWh/kg dry biomass in sonication. However, in biofuels production, the energy input must be minimized, requiring slower, thermal or chemical pretreatments. Whichever the primary fraction of interest, the spent biomass can be processed into valuable by-products. This review discusses microalgal cell structure and composition, how it affects pretreatment, focusing on technologies tested for large scale or promising for industrial processes, and how these can be integrated into algal biorefineries.


Assuntos
Microalgas , Biocombustíveis , Biomassa , Alimentos
10.
Bioresour Technol ; 300: 122741, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31956058

RESUMO

Algal bioremediation becoming most fascinating to produce biomass as biofuels feedstock while remediating wastes, also improving carbon-footprint through carbon capturing and utilization (CCU) technology. Non-algae process however offers effective treatment but metabolic CO2 emission is major drawback towards sustainable bioprocess. Mixotrophic cultivation strategy (MCS) enables to treat organic and inorganic wastes which broadly extend microalgae application towards cleaner and sustainable bioeconomy. Latest focus of global think-tanks to encourage bioprocess holding promise of sustainability via CCU ability as important trait. Several high CO2 emitting industries forced to improve their carbon-footprints. MCS driven microalgae treatment could be best solution for those industries. This review covers recent updates on MCS applications for waste-to-value (biofuels) and environment remediation. Moreover, recommendations to fill knowledge gaps, and commercial algal biofuel could be cost-effectiveness and sustainable technology for biocircular economy if fuelled by waste streams from other industries.


Assuntos
Recuperação e Remediação Ambiental , Microalgas , Biocombustíveis , Biomassa , Análise Custo-Benefício
11.
Bioresour Technol ; 301: 122762, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31972402

RESUMO

To assess the potential of Chlorella sp. GN1 for producing biodiesel raw materials in flat plate photobioreactors (FPPs) outdoors, we optimized the nitrogen sources and concentrations for the growth of the algae. The effects of different light paths of FPPs on the growth, lipid accumulation, and fatty acids of Chlorella sp. GN1 were also studied. As the light path of the FPPs was reduced, the alga could accumulate lipids rapidly, achieving high lipid content and lipid productivity outdoors. The highest lipid content obtained was 53.5%, when the light path was 5 cm. In addition, the lipid productivity was 66.7 mg L-1 day-1. The main fatty acids were C16/C18, accounting more than 90% of the total fatty acids. Results showed that Chlorella sp. GN1 had the ability to accumulate large quantities of lipids in FPPs outdoors and was a promising microalgal species for biofuel production.


Assuntos
Chlorella , Microalgas , Biocombustíveis , Biomassa , Ácidos Graxos , Luz , Lipídeos , Nitrogênio , Fotobiorreatores
12.
Bioresour Technol ; 301: 122804, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31982297

RESUMO

Biodiesel is one of the best promising candidates in response to the energy crisis, since it has the capability to minimize most of the environmental problems. Microalgae, as the feedstock of third-generation biodiesel, are considered as one of the most sustainable resources. However, microalgae production for biodiesel feedstock on a large scale is still limited, because of the influences of lipid contents, biomass productivities, lipid extraction technologies, the water used in microalgae cultivation and processes of biomass harvesting. This paper firstly reviews the recent advances in microalgae cultivation and growth processes. Subsequently, current microalgae harvesting technologies are summarized and flocculation mechanisms are analyzed, while the characteristics that the ideal harvesting methods should have are summarized. This review also summarizes the environmental pollution control performances and the key challenges in future. The key suggestions and conclusions in the paper can offer a promising roadmap for the cost-effective biodiesel production.


Assuntos
Microalgas , Biocombustíveis , Biomassa , Poluição Ambiental , Floculação
13.
World J Microbiol Biotechnol ; 36(2): 20, 2020 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-31955252

RESUMO

Vinasse is a waste from the alcohol industry that can support microalgal growth because of its mineral and organic contents. Growing microalgae on waste can be a means of its remediation and decrease culture costs. The physiological knowledge of microalgae on waste can generate subsidies to increase biomass productivity. However, few studies have explored the photosynthetic metabolism of microalgae on complex matrices such as vinasse. In the present research, we investigated some physiological aspects related to photosynthesis and growth of several microalgae in centrifuged and diluted vinasse. The species investigated were Chlamydomonas sp., Chlorella sorokiniana, Chlorella vulgaris, Desmodesmus spinosus, Haematococcus pluvialis, Monoraphidium sp., Scenedesmus quadricauda and Tetraselmis gracilis. Daily cell density, in vivo chlorophyll a and final cellular biovolumes (96 h) were monitored to infer about population growth. Maximum and operational photosynthetic yields (ϕM and ϕ'M), photochemical (qP) and non-photochemical (NPQ) quenchings, light saturation curves and related parameters (α, rETRm and EK), as well as theoretical carbon fixation were evaluated using pulse amplitude modulated fluorometry (PAM). The results showed that chlorophyll a, photochemical (qP) and non-photochemical (NPQ) quenchings were not affected in vinasse, but photosynthetic yields, light curves parameters and autotrophic carbon fixation decreased. Connecting these results to the increase in productivities in vinasse lead us to the rationale that mixotrophic metabolism was supporting microalgae growth on the waste. This study offers important insights into the understanding of microalgal photosynthetic physiology on complex organic wastes, generating subsidies for optimization of biotechnological use of vinasse related to microalgae production.


Assuntos
Carbono/metabolismo , Resíduos Industriais/análise , Microalgas/crescimento & desenvolvimento , Biodegradação Ambiental , Biomassa , Ciclo do Carbono , Clorofila A/metabolismo , Microalgas/metabolismo , Fotossíntese
14.
World J Microbiol Biotechnol ; 36(1): 17, 2020 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-31912247

RESUMO

In this study, the effects of limited and excess nitrate on biomass, lipid production, and fatty acid profile in Messastrum gracile SE-MC4 were determined. The expression of fatty acid desaturase genes, namely stearoyl-ACP desaturase (SAD), omega-6 fatty acid desaturase (ω-6 FAD), omega-3 fatty acid desaturase isoform 1 (ω-3 FADi1), and omega-3 fatty acid desaturase isoform 2 (ω-3 FADi2) was also assessed. It was found that nitrate limitation generally increased the total oil, α-linolenic acid (C18:3n3) and total polyunsaturated fatty acid (PUFA) contents in M. gracile. The reduction of nitrate concentration from 1.76 to 0.11 mM increased the total oil content significantly from 32.5 to 41.85% (dry weight). Palmitic (C16:0) and oleic (C18:1) acids as the predominant fatty acids in this microalgae constituted between 82 and 87% of the total oil content and were relatively consistent throughout all nitrate concentrations tested. The expression of SAD, ω-6 FAD, and ω-3 FADi2 genes increased under nitrate limitation, especially at 0.11 mM nitrate. The ω-3 FADi1 demonstrated a binary up-regulation pattern of expression under both nitrate-deficient (0.11 mM) and -excess (3.55 mM) conditions. Thus, findings from this study suggested that limited or excess nitrate could be used as part of a cultivation strategy to increase oil and PUFA content following media optimisation and more efficient culture methodology. Data obtained from the expression of desaturase genes would provide valuable insights into their roles under excess and limited nitrate conditions in M. gracile, potentially paving the way for future genetic modifications.


Assuntos
Ácidos Graxos Dessaturases/genética , Ácidos Graxos/análise , Microalgas/crescimento & desenvolvimento , Nitrogênio/metabolismo , Biomassa , Ácidos Graxos Dessaturases/metabolismo , Ácidos Graxos Insaturados/metabolismo , Regulação Enzimológica da Expressão Gênica , Metabolismo dos Lipídeos , Microalgas/genética , Microalgas/metabolismo , Ácido Oleico/metabolismo , Ácido Palmítico/metabolismo , Ácido alfa-Linoleico/metabolismo
15.
Environ Technol ; 41(3): 267-276, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29963975

RESUMO

Conventional treatments for nutrient removal in wastewater are shifting to Anaerobic Membrane Bioreactors, which produce a high-quality effluent with minimum sludge production. The effluent resulting contains high nitrogen and phosphorus load that can be eliminated by microalgae culture. The aim of this study is to evaluate the ammonium and phosphorus removal rate of different microalgae species in the effluent of an anaerobic treatment. For that, 4 different microalgae species have been tested (Chlamydomonas reinhardtii, Scenedesmus obliquus, Chlorella vulgaris and Monoraphidium braunii) in batch monoculture and mixed conditions. Results indicate that all species are able to eliminate both P and N in the medium with high removal rates. However, a slight interspecies competition may boost these removal rates and productivity values ensuring, the success of the process.


Assuntos
Chlorella vulgaris , Microalgas , Anaerobiose , Reatores Biológicos , Nitrogênio , Fósforo , Eliminação de Resíduos Líquidos , Águas Residuárias
16.
Environ Technol ; 41(5): 617-626, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30074855

RESUMO

The microalgae Chlorella vulgaris ATCC 13482 was used in the present study for municipal wastewater treatment. Batch experiments were performed in bubble column photobioreactors of 7 L working volume maintained at 25 ± 2°C and 14 h/10 h of photo and dark cycle. The treatment process was enhanced by using CO2-augmented air (5% CO2 v/v) supply into the microalgal culture in comparison to the use of normal air (0.03% CO2 v/v). For a period of 7 days, C. vulgaris effected maximum removals of 74.4% soluble fraction of chemical oxygen demand, 72% ammonia (NH4-N), 60% nitrate (NO3-N) and 81.93% orthophosphate (PO4-P) with use of normal air, whereas 84.6% sCOD, 88% NH4-N, 72% NO3-N and 92.8% PO4-P removals, respectively, with use of 5% CO2/air supply. Using kinetic study data, the specific rates of ammonia and phosphate uptake (qammonia and qphosphate) by C. vulgaris at 5% CO2/air supply were found to be 2.41 and 0.85 d-1, respectively. Using the algal remediation technology, nitrogen-phosphorus-potassium recovery from sewage treatment plant of 37.5 million litres per day wastewater influent capacity was calculated to be ∼298.5, 55.4 and 83.7 kg d-1, respectively.


Assuntos
Chlorella vulgaris , Microalgas , Biomassa , Dióxido de Carbono , Nitrogênio , Nutrientes , Fotobiorreatores , Águas Residuárias
17.
Bioresour Technol ; 297: 122462, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31791920

RESUMO

Exploiting solar energy for growing algal biomass in waters enriched with farm manures is a holistic method of waste management. The proposed cultivation strategy termed SAR'CENA ('Synergistic Algal Refinery for Circular Economy using Nutrient Analogues), involves integrated cultivation of microalga, Scenedesmus obliquus and marine macroalga, Ulva lactuca in litter to harness biorefinery products. From various litters tested, poultry litter manure (PLM) was most amenable for growth. The microalga yielded 410 ± 6.2 g·DW· m-2· d-1 of biomass with total nitrogen (TN) concentration of 70 mg·L-1 in the media, while the macroalgae yielded 334 ± 9.9 g DW m-2 d-1 of biomass with TN concentration of 17.5 mg·L-1. The nutrient uptake efficiency was observed to be >60% with uncompromised biomass composition. Thus, SAR'CENA is projected as an ideal farming solution incorporating efficient waste management and feedstock generation thereby establishing a circular economy towards clean energy.


Assuntos
Microalgas , Scenedesmus , Ulva , Animais , Biocombustíveis , Biomassa , Esterco , Aves Domésticas
18.
Bioresour Technol ; 298: 122421, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31767428

RESUMO

Coupling algae growth on wastewater with hydrothermal liquefaction (HTL) is regarded as an environment-enhancing pathway for wastewater management, biomass amplification, sustainable energy generation and value-added products generation. Through this integrated pathway, microalgae can not only recover nitrogen and phosphorus, but also absorb heavy metals from the wastewater. The migration and transformation of heavy metals need to be specifically assessed and considered due to the environmental concerns associated with metal toxicity. This work reviewed recent advances with respect to bioremediation mechanisms. Particular emphasis was placed on the heavy metal migration, transformation, and the key factors involved in algal wastewater treatment and biomass conversion. Additionally, the challenges of coupling algae wastewater treatment, hydrothermal conversion, and heavy metal control were addressed. Finally, a paradigm involving enhanced algal wastewater treatment and bioenergy production for field application was proposed.


Assuntos
Metais Pesados , Microalgas , Biocombustíveis , Biomassa , Águas Residuárias
19.
Bioresour Technol ; 297: 122509, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31812914

RESUMO

Dunaliella salina is well-known for its high content in carotenoids and glycerol. Nevertheless, Dunaliella salina has also a high content in lipids, including polar lipids, which are suitable for nutraceutical/cosmeceutical applications. This work proposes a sustainable process to maximise the potential of Dunaliella salina for the production of distinct fractions of carotenoids, glycerol, polar lipids and proteins, which may contribute to improve the revenues of the microalgae industry. In this work, extraction with non-hazardous solvents and organic solvent nanofiltration are integrated, in order to obtain added-value products and glycerol. Also, aiming to separate carotenoids from glycerides, a saponification process is proposed. High overall recoveries were obtained for carotenoids (85%), glycerol (86%), polar lipids (94%) and proteins (95%). In order to evaluate the profitability of the proposed biorefinery, an economic assessment was accomplished. Both CAPEX and OPEX (Capital and Operating expenditure) were calculated, likewise the Return of Investment (ROI).


Assuntos
Carotenoides , Microalgas , Glicerídeos , Glicerol , Lipídeos
20.
J Agric Food Chem ; 68(1): 402-408, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31809034

RESUMO

The functional ingredients of microalgal biomass are receiving substantial recognition as the global demands for health supplements produced from natural sources are on the rise. Paramylon, a conglomerate of ß-1,3-glucans, is one of the major valuable sources derived from Euglena gracilis having multiple applications, thus necessitating the development of an efficient quantification method. Here, we employed a DNA aptamer to quantify the amount of paramylon produced by E. gracilis. Paramylon-specific aptamers were isolated by the systematic evolution of ligands by exponential enrichment (SELEX) process. To evaluate the potential aptamers, the binding affinity between aptamer candidates and paramylon granules was confirmed by a confocal laser scanning microscope and the dissociation constants of the selected aptamers were determined by nonlinear regression analysis. The selected DNA aptamer was successfully used for the quantification of paramylon, and the results were compared to those obtained by the standard methods. The new approach was also used for quantification of paramylon from E. gracilis cells cultured to different cell stages and physiologies. It can be concluded that the aptamer-based protocol for the measurement of paramylon proposed in this study is highly accurate and comparatively less time-consuming.


Assuntos
Aptâmeros de Nucleotídeos/genética , DNA de Cadeia Simples/genética , Euglena gracilis/química , Glucanos/análise , Extratos Vegetais/análise , Técnica de Seleção de Aptâmeros/métodos , Aptâmeros de Nucleotídeos/química , DNA de Cadeia Simples/química , Euglena gracilis/genética , Euglena gracilis/metabolismo , Glucanos/metabolismo , Microalgas/química , Microalgas/genética , Microalgas/metabolismo , Extratos Vegetais/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA